Transfusion medicine Flashcards
Calcium derangement associated with massive transfusion + mechanism
- hypocalcemia
- Blood is anticoagulated with sodium citrate and citric acid [49]. Each 450 mL unit of blood (or 500 mL unit in Europe) contains 9 mmol of citrate. As a result, massive transfusion leads to infusion of a large amount of citrate.
Management of hypocalcemia following massive transfusion
- administer calcum only to treat symptomatic hypocalcemia
Presentation of hypocalcemia following massive transfusion
early → hyperactive DTR’s
severe → seizures, twitching, cardiac arrythmia (prolonged QT)
Indications for irradiated blood products
*immunocompromised
- transplant patients
- congenital t cell immunodeficiency
- heme malignancies
-intrauterine or neonatal transfusion
4) *fludarabine or cladribine
Why irradiate blood products?
Prevent transfusion associated GVHD
when is leukoreduction indicated?
1) CMV transmission risk
*History of febrile NHTR
*At risk for HLA alloimmunization (sickle cell pts, chronically transfused patients)
Indications for washing cell products?
1) history of anaphylaxis
2) IgA deficient
*neonatal or intrauterine transfusion
What is the risk associated with washing blood products?
hyperkalemia
Cause of acute hemolytic reactions?
ABO mismatch
Etiology of delayed hemolytic reactions?
transfusion recipient has antibodies that react with antigens on incompatible donor red blood cells (so ABO but also can be duffy, kell, kid, etc)
Time window for delayed hemolytic transfusion reaction?
5-14 days post transfusion
Febrile non hemolytic transfusion reaction mechanism
- cytokines and leukocytes in blood products
Febrile non hemolytic transfusion reaction 1) acute management 2) management of future transfusions
- supportive care w/ antipyretics
- leukoreduction for future transfusions
Etiology of urticarial reactions
Antibodies to donor plasma
1) Management of urticarial reactions 2) Can you continue transfusion?
1) benadryl
2) Yes, slowly
TRALI mechanism
Antibodies directed toward human leukocyte antigens (HLA) or human neutrophil antigens (HNA) have been implicated, with transfused antibodies shown to bind antigens expressed on pulmonary endothelial cells to initiate acute inflammation in the lungs
TRALI radiographic findings
- bilateral infiltrates (see photo online)
TRALI clinical features
acute hypoxemic respiratory failure + within 6 hours of transfusion + CXR is diffuse opacity
1) Management of anaphylaxis with transfusions 2) subsequent management
- supportive care w/ steroids + epi
- check IgA (CONFIRM)
2) washed products
Post transfusion purpura 1) timeframe 2) mechanism 3) management 4) clinical scenario 5) management of subsequent platelet transfusions
1) 5-14 days
2) antibodies to platelet antigens - patient develops antibodies to the HPA-1a antigen leading to platelet destruction
3) PLEX, IVIG
4) pregnant patient
5) ***transfuse HPA-1a antigen negative platelets
Infectious risks of transfusion
HIV - 1 in 1.5 million
Hepatitis - 1 in 1 million
Bacteria - 1 in 75k
In what blood product is bacterial transmission more common?
- platelets (stored at room temp)
What infections are screened for in the US
- HIV
- hep b and c
- HTLV
- west nile
- syphilis
- chagas
- babesia
- malaria if recent travel
Highest risk pathogen in transfusion
hep b